Conventionally, as a vehicle lock device, for example, a vehicle seat lock device as disclosed in Patent Document 1 is known. The lock device includes a base member including a base groove, into which a striker can be inserted, and a latch including a latch groove that can be engaged with and disengaged from the striker. The base groove and the latch groove restrain the striker, and a pawl restricts the rotation of the latch so that the locked state of the striker is maintained. In the locked state, a protrusion formed on the latch is pressed by a cam member according to the urging force of a spring so that the latch is rotated (urged) in the locking direction to reduce the backlash of the latch in the locked state.
The latch and the pawl are supported on the base member via different rotation shafts and arranged in the same plane perpendicular to the rotation shafts. Also, the pawl and the cam member are coaxial and stacked in the axial direction.
When the latch in the locked state receives a major load in the releasing direction (unlocking direction), the pawl sustains the load. The cam member reduces the backlash in the locked state by the urging force of the spring. As mentioned above, the functions of the pawl and the cam member are clearly distinguished. For example, even if the function of the cam member is impaired, the function of the pawl, i.e., the function of maintaining the locked state, is guaranteed. That is, when a major load is applied to the latch, the cam member is not configured to sustain the load.
Accordingly, in the configuration in which the pawl and the cam member are coaxially arranged, it is necessary to ensure the range of rotation of the pawl, i.e., the range of the engagement of the pawl with the latch basically in accordance with the range of rotation of the cam member, which is rotated together with the pawl. Therefore, the amount of rotation of the pawl at the time of unlocking is increased. Thereby, the amount of operation of a control lever associated with the unlocking operation is increased as well so that manipulability and appearance are impaired.
Accordingly, for example, in the vehicle seat lock device disclosed in Patent Document 2, the pawl and the cam member are supported on the base member via different rotation shafts, and the pawl and the cam member are linked by a linkage. Thereby, it is assumed that the ranges of the rotations of the pawl and the cam member are independent from each other, or the timing of locking and unlocking (releasing) by the pawl and the cam member is arbitrarily adjusted.